This chapter offers a historical explanation for the poor Mexican tax state. It proposes that the Revolution (1910–1917) opened a window for change. However, the construction of a revolutionary tax system was highly contested, and over time this project was forgotten. Based on the theoretical concepts of the instrumental and structural power of economic elites, the failure to build a revenue-raising and progressive tax system is analyzed as the result of the consolidation of an alliance between the Mexican state and its economic elite. This alliance prioritized the promotion of private capital accumulation in the interest of economic growth (industrialization) and political stability, which translated into a poor tax state in the fiscal sphere. Based on archival research, I present an original account of the policy-making process behind the most important tax reforms between 1925 and 1964 and the actors involved. It shows the nonlinear process of consolidating a pro-growth alliance characterized by low taxation of the elites that continues to explain the structural weakness of political decision-makers vis-à-vis the economic elites. I also discuss competing explanations for the Mexican state's low fiscal performance, particularly the importance of alternative resources (such as oil revenue, debt, or revenue from state-owned enterprises).